MP24-17: Prospective Validation and Comparison of Different Scoring Systems for the Prediction of Surgical outcome of Robot-assisted Partial Nephrectomy

Cesare Saitta*, Pietro Diana, Alessandro Uleri, Vittorio Fasulo, Andrea Gobbo, Paola Arena, Edoardo Beatrici, Giuseppe Chiarelli, Roberto Contieri, Nicola Frego, Pier Paolo Avolio, Davide Maffei, Alberto Saita, Paolo Casale, Giorgio Guazzoni, Massimo Lazzeri, Rodolfo Hurle, Giovanni Lughezzani, Nicolò Maria Buffi, Milano, Italy

Introduction: Robotic-assisted partial nephrectomy (RAPN) have changed the treatment of localized renal cancer permitting to treat more challenging cases in a safer way. Numerous scoring systems have been developed providing an accurate tool capable of preoperatively predicting surgical outcomes based on tumor complexity. The recent introduction of the Simplified PADUA Renal (SPARE) score has found interest in this setting as simpler and more accurate. The aim of our study was to prospectively record the performances of the PADUA (P), R.E.N.A.L (R) and SPARE (S) nephrometry scores.

Methods: In this prospective study we enrolled 113 consecutive RAPN performed between 2019 and 2021. R, P and S scores were calculated. Optimal surgical outcomes were defined according to the Margin, Ischemia and Complications (MIC) score: surgical margin negative, ischemia time less than 20 minutes, and post-operative complications classified by Clavien-Dindo (CD) scale >2. Logistic regression models were fitted to test the predictors of achieving MIC. Finally, the accuracy of each score to predict surgical outcomes was determined as area under the receiver operator characteristic (ROC) curve.

Results: Of 113 patients, 72 were males; the median age was 58 years (IQR 51-65). The median clinical size was 30 mm (IQR 20-40). Median warm ischemia time was 12 minutes (IQR 10-16); median estimated blood loss was 70 ml (IQR 50-100). All RAPNs were performed transperitoneally and total arterial clamping, selective clamping, and no clamping were performed in 74.3%, 16.8%, and 8.9% of the cases, respectively. Overall, 33.62% of patients developed CD>=1 postoperative complications, and 7.43% were classified as CD >2. MIC was achieved in 91 cases. Patients were stratified according to the three nephrometry scores in: low risk (L), intermediate risk (I) and high risk (H). Only the P and the S correlate with not achievement of the MIC. P: I vs L OR=4.55 p=0.02; P: H vs L OR=5.25 p=0.06. S: I vs L OR=4.34 p<0.01; S: H vs L: OR=8.25 p=0.04. R: I vs L OR=1.58 p=0.35. 

 Finally, in the ROC analysis the accuracy of, P, S and R scores were respectively: 0.66 (CI 95%=0.55-0.77), 0.68 (CI=0.56-0.80) and 0.56 (CI=0.44-0.67). When compared the areas under the curves between P and S no statistical differences emerged (p=0.46)

Conclusions: In our prospective series, the currently available nephrometric scores showed a heterogeneous and suboptimal performance in predicting MIC score of patients undergoing RAPN. Our data suggest the need of developing more accurate nephrometric scores.

Source of Funding: None.